1. Field of the Invention
The invention relates to automotive wheel suspensions in general and, more particularly, to wheel suspensions adapted to compensate for, or balance, transverse forces generated as a function of the wheel being raised or lowered when subjected to varying loads. While generally applicable to allautomotive wheel suspensions, the invention will hereinafter be described in connection with independent wheel suspensions by way of preferred embodiments.
2. Description of the Prior Art
In certain independent wheel suspensions the wheel when rolling over an uneven surface or when subjected to varying loads may be raised and lowered along an arcuate path substantially coinciding with the periphery of a circle the radius of which is defined by a wheel control arm one end of which may be pivotally connected to the frame of the vehicle and the other end of which may be connected to the hub of the wheel. Lowering and raising of the wheel may be balanced or dampened by a suspension strut combining, as a telescoping unit, a shock absorber and a spring. The spring may in fact be a pneumatic spring formed by a substantially tubular rolling bellows or lobe pressurized in a manner well known in the art. As will be appreciated by those skilled in the art the movement of the wheel, hereafter referred to as "vertical movement" subjects the strut, and more particularly the shock absorbing portion thereof, to considerable transverse forces which may lead to rapid deterioration of the apparatus.
Attempts have, of course, been made to reduce such transverse forces and their adverse effect on the apparatus, but they have not, by and large, met with the desired success. One known structure of this kind is disclosed in west German patent specification DE-OS No. 20 63 448. In the arrangement disclosed in that specification a spring force compensating force acting transversally on a pneumatic spring is generally by positioning the substantially cylindrical rolling bellows of the spring obliquely, i.e. at a predetermined angle, relative to the longitudinal or center axis of the strut. The oblique positioning of the spring element is accomplished by inclining an upper seat or support surface to which the spring element is attached. The seat or support plate and the piston rod of the shock absorber are mounted to the frame of a vehicle by way of a common rotary bearing. An elastic rubber support may be placed between the rotary bearing and the frame in order to insulate driving noise otherwise penetrating from the drive arrangement to the frame.
Such a construction makes possible only partial compensation or balancing of the transverse forces which affect the piston rod bearing and the piston of the shock absorber in a particularly detrimental manner. Furthermore, the relatively strong angular inclination of the spring element or rolling lobe leads to other structural, spatial, and functional disadvantages, as will be appreciated by those skilled in the art.
It is, therefore, an object of the present invention to provide a novel wheel suspension which is free of the disadvantages of prior art devices.
Another object resides in the provision of a wheel suspension which substantially eliminates or balances transverse forces acting on the suspension strut of a wheel suspension.
A further object of the invention is to provide a wheel suspension in which transverse forces otherwise affecting the strut are substantially eliminated without requiring additional parts for the assembly.
It is also an object to provide a wheel suspension which by the simple expedient of aligning the forces of the spring with the resultant of the forces generated as a result of vertical movement of the wheel compensates or balances the transverse forces to reduce excessive wear of the shock absorber.
A further object of the invention is to eliminate, or at least substantially reduce, forces acting transversally of a strut in a wheel suspension of the kind referred to with simple means and in an economical manner.
Yet another object is the provision of a wheel suspension including a suspension strut of the kind comprising, in telescoping alignment, a shock absorber and a pneumatic spring element, in which the resultant of the forces generated as a result of vertical movement of the wheel under varying loads is drawn upon to determine the disposition of the spring element relative to the shock absorber for balancing or compensating the transverse forces.